From Stefan Rahmstorf and the Potsdam Institute for Climate Impact Research (PIK)
Expert assessment: Sea-level rise could exceed 1 meter in this century
In contrast, for a scenario with strong emissions reductions, experts expect a sea-level rise of 40-60 centimeters by 2100 and 60-100 centimeters by 2300. The survey was conducted by a team of scientists from the USA and Germany.
“While the results for the scenario with climate mitigation suggest a good chance of limiting future sea-level rise to one meter, the high emissions scenario would threaten the survival of some coastal cities and low-lying islands,” says Stefan Rahmstorf from the Potsdam Institute for Climate Impact Research. “From a risk management perspective, projections of future sea-level rise are of major importance for coastal planning, and for weighing options of different levels of ambition in reducing greenhouse-gas emissions.”
Projecting sea-level rise, however, comes with large uncertainties, since the physical processes causing the rise are complex. They include the expansion of ocean water as it warms, the melting of mountain glaciers and ice caps and of the two large ice sheets in Greenland and Antarctica, and the pumping of ground water for irrigation purposes. Different modeling approaches yield widely differing answers. The recently published IPCC report had to revise its projections upwards by about 60 percent compared to the previous report published in 2007, and other assessments of sea-level rise compiled by groups of scientists resulted in even higher projections. The observed sea-level rise as measured by satellites over the past two decades has exceeded earlier expectations.
Largest elicitation on sea-level rise ever: 90 key experts from 18 countries
“It this therefore useful to know what the larger community of sea-level experts thinks, and we make this transparent to the public,” says lead author Benjamin Horton from the Institute of Marine and Coastal Sciences at Rutgers University in New Jersey. “We report the largest elicitation on future sea-level rise conducted from ninety objectively selected experts from 18 countries.” The experts were identified from peer-reviewed literature published since 2007 using the publication database ‘Web of Science’ of Thomson Reuters, an online scientific indexing service, to make sure they are all active researchers in this area. 90 international experts, all of whom published at least six peer-reviewed papers on the topic of sea-level during the past 5 years, provided their probabilistic assessment.
The survey finds most experts expecting a higher rise than the latest IPCC projections of 28-98 centimeters by the year 2100. Two thirds (65%) of the respondents gave a higher value than the IPCC for the upper end of this range, confirming that IPCC reports tend to be conservative in their assessment.
The experts were also asked for a “high-end” estimate below which they expect sea-level to stay with 95 percent certainty until the year 2100. This high-end value is relevant for coastal planning. For unmitigated emissions, half of the experts (51%) gave 1.5 meters or more and a quarter (27%) 2 meters or more. The high-end value in the year 2300 was given as 4.0 meters or higher by the majority of experts (58%).
While we tend to look at projections with a focus on the relatively short period until 2100, sea-level rise will obviously not stop at that date. “Overall, the results for 2300 by the expert survey as well as the IPCC illustrate the risk that temperature increases from unmitigated emissions could commit coastal populations to a long-term, multi-meter sea-level rise,” says Rahmstorf. “They do, however, illustrate also the potential for escaping such large sea-level rise through substantial reductions of emissions.”
Article: B. P. Horton, S. Rahmstorf, S. E. Engelhart, A.C.Kemp: Expert assessment of sea-level rise by AD 2100 and AD 2300. Quaternary Science Reviews (2013). [doi: 10.1016/j.quascirev.2013.11.002]
Link to the article when it goes online: http://dx.doi.org/10.1016/j.quascirev.2013.11.002
============================================================
The basic premise of Stefan Rahmstorf’s claim is that sea level rise will accelerate before the end of the century. So far there has been no evidence of acceleration, it appears entirely linear no matter whether we look at tide gauges or satellite measurements.
The image below (From Holgate 2007 On the decadal rates of sea level change during the twentieth century in GRL) shows Holgate’s reconstruction of the sea level rise rate for the 20th century from the highest quality tide gauge data.
![holgate-9-station-with-std-dev-digitized[1]](http://wattsupwiththat.files.wordpress.com/2013/11/holgate-9-station-with-std-dev-digitized1.jpg?quality=83)
As you can see, the sea level rise rate widely varied during the 20th century. It reached about 4 mm/year around 1911, and again in the 1930s, 1950s and around 1980. It was much lower in the 1920s, 1940s, 1960s and mid-1980s.
Holgate concludes:
Based on a selection of nine long, high quality tide gauge records, the mean rate of sea level rise over the period 1904–2003wasfoundtobe1.74±0.16mm/yr after correction for GIA using the ICE-4G model [Peltier, 2001] and for inverse barometer effects using HadSLP2 [Allan and Ansell, 2006]. The mean rate of rise was greater in the first half of this period than the latter half, though the difference in rates was not found to be significant. The useof a reduced number of high quality sea level records was found to be as suitable in this type of analysis as using a larger number of regionally averaged gauges.
For satellite measurements there also doesn’t seem to be any acceleration.
German veteran meteorologist Klaus-Eckart Puls has done an analysis of sea level rise. Contrary to many claims, we see that sea level rise has decelerated markedly since 2003.
![Puls_2[1]](http://wattsupwiththat.files.wordpress.com/2013/11/puls_21.jpg?quality=83)
– See more at: http://notrickszone.com/2012/12/06/meteorologist-klaus-eckart-puls-sea-level-rise-has-slowed-34-over-the-last-decade/#sthash.h1npSYgJ.dpuf
So, neither tide gauges nor satellite measurements suggest acceleration is occurring. Even if we use the worst case value, 3.2 mm/year cited by CU in a linear calculation…
…we get this:
years left 2100-2013= 87 years
3.2 mm/year * 87 years = 278.4mm or 0.2784meter…about a quarter of the 1 meter (or more) claim made by Rahmstorf.
Rahmstorf isn’t working in reality.
Related articles
- IPCC’s New Estimates for Increased Sea-Level Rise (yaleclimatemediaforum.org)
- Scientists Find That Sea Level Rise Is Much Slower Than Expected…No Human Fingerprint (notrickszone.com)
- IPCC sea level exaggeration (wattsupwiththat.com)
Whatever anyone says these creatures will not deviate from their message. Bad monkey. If you keep burning stuff you will drown. (after I am tenured/retired/dead)
Oh no, not more expert projections. How many times have these “experts” been correct?
… according to the first paragraph, Rahmstorf is suggesting 40 – 60 cm. by 2100, not a meter, as alluded to in your final paragraph.
For the record.
The linear fixation is based on either a belief in or a refutation of the linear effect of rising CO2 concentrations. That is the falicy that needs to be beaten down. All fall from that.
But it’s a consensus of experts so it must be right!
A friend of mine defined “expert” this way: A drip under pressure. And these so-called experts are under pressure to make themselves look right, regardless of the facts.
That first graph isn’t showing an 11 year cycle, or is it? Oh, maybe it is.
http://wattsupwiththat.com/2009/04/07/archibald-on-sea-level-rise-and-solar-cycles/
If they’re picking numbers under-which they’re at 95% confident the sea level rise would stay, sounds like high numbers are looking good 😉
If someone asked me what I’m 95% confident the December-January high temperature in Chicago will stay under, 100°F sounds like a good number… 200° would also work 😉
Now, if they were asked for a number above-which they were 95% sure the sea level rise would exceed… I bet we’d see a much different picture.
New paper finds sea level rise has decelerated 44% since 2004 to only 7 inches per century
http://hockeyschtick.blogspot.com/2013/11/new-paper-finds-sea-level-rise-has.html
if the actual issue is sea level (where the water comes up to on land) then the GIA correction needs to be removed. with the addition of the GIA correction, it seems that they are more interested in sea volume than sea level
“While we tend to look at projections with a focus on the relatively short period until 2100, sea-level rise will obviously not stop at that date.”
Do we really know with any certainty that it will not stop at that date? It has to stop at some point. I guess the word “obviously” is meant to squelch that question.
Germans dilute EU auto emissions standards, the new EU tighter standard is the only reason BMW, Porsche and Mercedes are producing loss making electric vehicles, nail in electric coffin.
Seems Merkal is more concerned in supporting the German car industry than sea level rise.
OT: Climate Scientists and Lawyers… And SuperMandia
http://www.straight.com/news/535376/climate-scientists-get-lawyered
“The American Geophysical Union, representing more than 62,000 Earth, atmospheric, and space scientists worldwide, has teamed with the Climate Science Legal Defense Fund to make lawyers available for confidential sessions with scientists at its annual meeting next month.”
And
“It’s an issue few researchers contemplate as they prepare for a career in science, said Scott Mandia, professor of physical sciences at Suffolk County Community College in New York and founder of the Climate Science Legal Defense Fund.”
==
When science does not suffice… get a lawyer! LOL
Is there a quantified breakdown into the magnitude of the different components that make up the predicted one meter rise. eg thermal expansion, melting glaciers, melting Greenland, melting Antarctic, what else? Which are the big contributors? It would then be interesting to look at the evolution of the history of each component so that necessary changes in rate can be pinned down and the underlying expected components more deeply examined as too root cause of change.
It will be far more interesting than holding a poll.
“The experts were also asked for a “high-end” estimate below which they expect sea-level to stay with 95 percent certainty until the year 2100.”
Nothing like making sure you get the high value you are wanting to appear.
I’m not normally one to comment here, but looking at the “worst case”…
In just under 300 years, sea levels *may* have risen by 1m. In 3 centuries – 1m. If I were still alive, if I’d stood still at the high water line, my groin would now be underwater – and I’m not very tall.
We’ve put a man on the moon. We’ve got a 30 year old space probe at the heliopause, at the edge of our solar system. We’ve got telescopes in space that can analyzer the atmospheres on planets hundreds of light years away. There is a nuclear powered partially autonomous robot tank trundling around another planet FGS.
And they’re worrying about a 1m rise in sea level.
What are we? Men or Mice? Our forebears colonised a hostile world, and some of us are losing sleep over the fact that in 3 centuries, the sea may be very slightly higher than it is now.
Adapt or die people.
“Overall, the results for 2300 by the expert survey as well as the IPCC illustrate the risk that temperature increases from unmitigated emissions could commit coastal populations to a long-term, multi-meter sea-level rise,” says Rahmstorf”
Projecting out to the year 2100 has an extreme amount of uncertainty. Going to 2300 is totally absurd. The world will have run out of fossil fuels to burn centuries earlier. There will either be a new source(s) to replace it or humans will have long since run out cheap energy and the rapidly diminishing supplies cost multiple times what we pay now and only the rich can afford, the small amounts left. This should play out well before the end of this century.
The “results for 2300” and “expert survey” are a contradiction. No authentic expert (knowledgeable of factors mentioned above) in this field would project to the year 2300. This is 200 years beyond outlandish.
Professional – a person who earns a living doing something, who sometimes makes a mistake but who learns from it, picks up the pieces and carries on a wiser person.
Expert – a person from the next-but-one city with a suit and a laptop.
“Expert assessment: Sea-level rise could exceed 1 meter in this century”
Common sense assessment: SLR, which has been rising at about 6″ per century for centuries will probably continue to do so, or even decline slightly due to expected cooling.
Henry Galt says:
November 22, 2013 at 8:17 am
Whatever anyone says these creatures will not deviate from their message. Bad monkey. If you keep burning stuff you will drown. (after I am tenured/retired/dead)
———————————————————–
The pseudoscience is settled.
Sea Level! And so, since there is nothing we could do about it, even were it true, and even were it due to activities of people ( which it is not) as opposed to naturally occuring events, and since China and India are not going to change their ways, WTF? Most of us do not live on the coast, in any event, and the costs of even trying to change it in terms of human suffering are probably greater than any potential benefits, assuming one could do anything about it. Forgetaboutit.
Stefan Rahmstorf has a conflict of interest, that might account for his disagreements with reality. He’s bankrolled by Munich Re, the giant German reinsurance company, and his scaremongering is money in the bank to them, because they can use it to justify higher reinsurance rates.
“It turns out that Rahmstorf has pulled an elaborate practical joke on the Community…”
– Steve McIntyre
More on Rahmstorf here: http://tinyurl.com/rahmstuff
More on sea level here: http://www.sealevel.info/
Pete Smith;
We’ve put a man on the moon. We’ve got a 30 year old space probe at the heliopause, at the edge of our solar system. We’ve got telescopes in space that can analyzer the atmospheres on planets hundreds of light years away. There is a nuclear powered partially autonomous robot tank trundling around another planet FGS.
>>>>>>>>>>>>>>>>>
Repeated for effect.
TomRude says:
November 22, 2013 at 8:58 am
“It’s an issue few researchers contemplate as they prepare for a career in science, said Scott Mandia, professor of physical sciences at Suffolk County Community College in New York and founder of the Climate Science Legal Defense Fund.”
Hack professor at Podunk Community College? It’s mildly amusing that this putz thinks he has a “career in science”
Pete Smith says:
November 22, 2013 at 9:14 am
Thanks Pete – very well put. Adapt or die…….our ancestors did. Why are we such timid creatures all of a sudden?